This invention relates generally to bearingless machines, and more specifically to an apparatus and method for assembling, storing, and transporting bearingless machines.
Bearingless machines, including Permanent Magnet (“PM”) motors and generators have been in use for many years. They have been favored over other types of electric machines for their efficiency, simplicity, robustness, and their tolerance to large radial air gaps between the rotor and the stator. As is well known, the simplest forms of PM motor/generators include an inner rotor assembly rotating concentrically within an outer stator assembly. The rotor assembly has one or more permanent magnets with poles disposed diametrically about a rotor shaft. As the magnet(s) are rotated by motive power connected to the shaft, the rotating magnetic fields generate an electrical current in one or more adjacent winding circuits disposed circumferentially around the outer stator assembly. Similarly, currents induced in the winding circuits induce magnetic fields that can cause rotation of the shaft. A gearbox, such as a planetary gearset or other mechanical transmission can be used to efficiently transfer rotational energy to and from the shaft depending on the operating mode of the vehicle or other machine.
It is often desirable in manufacturing and logistics to provide complete modular components or systems as they move along the supply chain to improve efficiency during the various stages of assembly. Transportation of these components is also helpful when these components or systems are compact with a minimum amount of air or empty space being moved. For example, a bearingless machine can be transported from a supplier to the next node in the manufacturing network with the rotating and stationary subassemblies as separate entities. At the very least, this is a waste of valuable shipping space given that the rotating subassembly is sized to fit within the stationary subassembly. However, one or both subassemblies can be damaged without some way of keeping the rotor element(s) separate from the stator elements.